Just got myself a Kawasaki KX 125 1992 Model, Advise required please !

[TaKeN]

I paid ?550 for an old 92 125 last weekend, the bike has just had a new piston and two new gears + selector fork.


After riding round and gently bedding in the piston i noticed some black oily substance running down the right hand side of my engine out of a small rubber cover, i think this is excess oil from the power valve due to the wrong ratio of oil to petrol mixture.

Please can someone confirm this, I have also noticed that when the bike is quite warm the power band kicks in and sometimes blips in and out as if the valve is opening and closing alot, I think this is due to the bike not firing properly but it doesnt seem to happen when the bike has just been warmed up.


I put 75w in the gearbox because i had to replace a leaky seal, but the castrol website recommends 10w-40 which is engine oil for four strokes ? :S


I will also be purchasing a bottle of Castrol TTS to run with the petrol for ultimate protection,

Is there anything else i need to look at or worry about , i'm slightly unsure of some things because this is my first motocross bike 


Thanks in advance 

[TaKeN]

* BUMP * Anyone help me please ?


Also, is 32 : 1 an ok ratio of fuel to oil mixture for a bike with a new piston ?


The Castrol TTS Fully Synthetic is meant to be mixed at this ratio, but 20 : 1 seems a safer bet to me.. 

[TaKeN]

Anyone please !

I need to set my bike up ready for some weekend riding !

[FuriouSly]

Hey there.  You know there are alot of factors that will effect how your bike runs.  Since you have just bought the 92 KX125, there can be alot of things out of sorts on it.  Do some searching on the site for jetting/carb/motor/modification setup info.

75w is fine for the tranny.

32:1 is a heavy mix and 40:1 would be fine.  (40 parts fuel to 1 part premix oil)

The oil leakage is prob the seal on the KIPS shaft out of the tranny side case, not going to effect performance right now just get a new seal on the way.  The oil is gear oil, not fuel/premix residue.

Main jet of 162/160 at 2000 feet or lower, needle cip on third notch, and mix screw 2 turns out would be good start for a basic stock KX125.

NGK BR9EG plug for all around riding.  A BR8 plug may be too hot for the bike in present condition.  The bike running funny can be a too lean/too hot condition.

Always good to start with a larger main jet and work your way back down.

Sly

[Johnniespeed]

 Hope you like your new bike. Do you happen to know how many US dollars is  the same as 550 pounds ?
   Gear oil is rated differently than engine oil for viscosity.  I ran accross a chart but cannot find it now.  I believe  that the 75 weight gear oil is very close to 10-40 engine oil as far as
viscosity is concerned.
  My KX owners manual recommends 32:1 fuel mix, but after inspecting the cylinder and piston, I realized that is way too much oil for me. I am currently using 40:1 but am probably going to switch to 50:1. Todays synthetic premix oils are light years ahead of yesterdays fossil based oils.
  The kips seal under the rubber cover, may have simply fallen out of its bore, mine fell out on the first day of ownership when the  bike was brand new. I very simply pressed it back into it's bore and it has never leaked again. 
  Hope this helps . John

[TaKeN]

Roughly $1,050.80 USD


Bikes over here in the UK Are very expensive


I did a new fuel mix today of 5 Litres of Petrol with 200 ML of Castrol TTS Which is a ratio of 25-1.


The bike ran ok, but wouldn't pick up so i diluted it down a bit by adding 2 Litres of fuel to my tank, this gives a ratio of.. 35 - 1 ( If my Maths is correct :p )


The bike ran much better after this but the power still seems quite jittery at times, I will inspect the air filter tommorow and see if its clogged with rubbish.


After riding for roughly 15 minutes tearing up and down my field almost flat out there was A LOT of smoke coming from the bike, so i let the bike idle for 5 seconds and it sounded fine, I looked at the Exhaust silencer and it was RED HOT INSIDE, the Metal Meshing was glowing red and all the unburnt oil from the Previous Owners excessive oil mix was being burnt away, There were also a few red sparks coming out which should just be rust from the red metal of the silencer,

I imediately took the bike home and inspected the plug. It wasnt white hot, or brown, and it wasn't black, It was a Dark earth color which tells me that the bike isn't being harmed ( I think thats correct )

Any ideas what caused the silencer to get so d**n hot ?

Should i add more petrol to my bikes fuel tank to adjust the ratio ?

Thanks for all the help so far

[MadKaw]

the packing in the silencer may be a bit full of gunk dur to the oil rich mix that was used. might need to be replaced or repacked. good luck!

[TaKeN]

UPDATE.


Ive ran the bike up this morning and its runnning like a shed.
 

Im beggining to hate it, the bike isnt firing properly at all when im on it, yet if i rev it when its stationary it runs fine

[TaKeN]

Ive asked someone to diagnose the problem ( he rides motocross )


He says the bike is missfiring... it doesnt do this when its sat there being rev'd when stationary.



He says to try 100ml of Oil to 5 Litres of Gas


and to repack the silencer on the bike because its got no packing..



PLEASE PLEASE PLEASE Can Someone Help me !!!!! Thanks In Advance

[TaKeN]

Another update, i was going to repack the silencer at the rear of the bike when i found it was already packed and ok.


then i spotted a large split where the weld to the silencer had broken, someone must have flipped the bike at some point and done this.



Ive welded it up but it was dark when i finished so there was no time to test.


Can someone please give me some advise on what causes a bike to missfire at top end when under load ?

and what to adjust,


PLEASE CAN SOMEONE HELP ! Nobody is replying, if im not explaining this properly then please say.


I'm tearing my hair out here because people are reading and nobody is replying

[eprovenzano]

I need a little more info.  What plug are you running? What fuel mix ratio are you running.  Did the bike sit for a while prior to your purchase?  When was the last time the top end was redone, (piston and rings).  Does the bike smoke a lot?

I know its frustrating, but I don't think there is anything "major" wrong.  We just need more info to help figure out the problem.

[TaKeN]

Thankyou very much for your reply.


The engine had a new piston and rings about a month ago.


The fuel to oil mixture is 35 - 1


The bike sat for two weeks before i bought it.


The bike does smoke alot when its cold, but once warm it doesn't.


When i rev the bike on its stand there is some white smoke that comes  out, but its not thick white smoke, just a hazy light smoke like a cigarette burning.


Once again, thanks for your help

[eprovenzano]

Fuel ratio 35:1 is fine.  What plug are you running?  When was it last changed? When was the air filter serviced last? 

You say it misfiles when under a load, but revs fine on the stand.  Stupid question, but are you trying to run wide open before the bike is warmed up?   When you say "misfires" does it feel as though it may be fuel related, too much or too little, or cuts out as thought its electrical. 

Based on your description, I'd bet its fuel related. (Of course I'm usually wrong)  Pull the carb, and check the float.  It may be set to low, where as there's not enough fuel available to pull under a load.  While the carb is off, give it a proper cleaning, check the jets, and make sure the needles are not bent.

Put in a fresh plug, NGKBR9, service the filter, reinstall the carb.  Make sure its properly warmed up, and give her a go.

Keep us informed as to your findings.  We need to eliminate the differect causes, lets work on the fuel system first.

[don46]

Typically the bike will rev fine when on the stand and not under a load, based on your description of the plug it sounds about right. Even though the silencer has packing it may be saturated with oil and need replacement. I had a bike that missed on the top end like you described, repacked the silencer and miss was gone. I have had problems with the kill buttons, they are not shorted, but evidently they are going to ground a little causing a misfire under a load, unplug the wire from the ignition and try it, you should be able to uplug it  to try, I think it's a black wire with a white stripe.

[TaKeN]

Thanks again for the advise,


I removed the filter last weekend and cleaned it, Dryed it out then re=oiled it.


I also completely cleaned out the carb and blew compressed air through the jets.


I will try a new plug and the kill switch idea, The plug might actually be the cause because its misfire seems either spark or fuel related but more fuel related


I'm going to sleep now because its 11.10 Pm here, thanks again lads.

Night